The Idaho showing is situated 600 metres southeast of the Similkameen River, 16 kilometres south of Princeton.

The area is underlain by the eastern facies of the Upper Triassic Nicola Group consisting of mafic augite and hornblende porphyritic pyroclastics and flows. These rocks are intruded by diorite and monzonite, locally pyroxenite and gabbro, of the Early Jurassic Copper Mountain and Lost Horse intrusions.

Syenodiorite of the Copper Mountain stock (Copper Mountain Intrusions) is cut by potassium feldspar porphyry dykes carrying copper mineralization. The dykes become larger and more numerous to the west. They appear to be related to the syenite pegmatite body outcropping along the Similkameen River in the core of the Copper Mountain stock.

Chalcopyrite and malachite occur in thin, short fracture fillings in the dykes. The fractures generally strike west and dip steeply north. A grab sample of this mineralization taken from a cliff face assayed 0.35 per cent copper and 1.0 grams per tonne gold (Assessment Report 2792, page 5). Similar mineralization occurs several hundred metres to the northwest on the Gouldie and Trachyte Crown-granted claims. Five chalcopyrite occurrences lie in an area up to 140 metres wide, extending 460 metres eastward from the Similkameen River. These occurrences are hosted in syenodiorite and syenite pegmatite of the Copper Mountain stock.

Cumont Mines Ltd. conducted geological, soil and magnetometer surveys over this showing in 1966 and 1970.